一种基于圆环点的相机定标方法

提出了一种基于圆环点求解相机内参数的方法．该方法要求相机在至少3个不同方位摄取一个含有若干条直径的圆图像，提取图像中的椭圆和直线，利用相切的射影不变性确定灭点及消隐线，通过消隐线和椭圆求交计算圆环点的图像坐标，从而线性求解全部相机内参数．整个过程既不需要对模板进行精确度量，也不涉及图像匹配问题．大量的模拟和真实图像实验结果表明，该方法精确度高，鲁棒性强．

Camera calibration method based on circular points

An easy method for computing a camera internal parameters based on circular points is proposed. The proposed method only requires the camera to observe a planar calibration pattern which includes a circle and a pencil of its diameters, from at least three different orientations, and either the camera or the planar pattern can be moved freely. The motion need not be known, vanishing points and the vanishing line can be determined using the invariant of tangency, circular points can be computed through the intersection of the vanishing line with the ellipse, and then all the five intrinsic parameters can be determined linearly. The whole process needs to know neither any metric measurement on the model plane, nor the correspondences between points on images. Extensive simulations and experimental results with real images show that the proposed technique is both accurate and robust.